The present invention relates to a method for the substitution of a first reel of strip material which is running out, with a second, new reel on an operating utiliser machine.
In machines such as, for example, cigarette wrapping machines, in which strip material, for example paper strip wound on a reel is used, it is necessary to effect substitution of a reel which is about to run out with a new reel without any break in the continuity of the strip which is undesireable for the good operation of the machine. For the purpose of resolving the above problem it is known to use an automatic reel changing device in which the strip running out and a strip wound on a new reel, one on the other, are made to advance at the same speed, simultaneously cut by means of a shear and then connected together with the tail of the old strip in contact with the head of the new strip along the line of cut.
The automatic reel changing device described above has numerous disadvantages mainly due to the fact that the new strip, once cut, can only be made to advance at the same speed as the old strip by thrust and not by traction. This fact affords notable difficulty in maintaining the two strips in contact along the line of cut before being connected together. Very often, in fact, it happens that the strips, once cut, become slightly spaced from one another forming a discontinuity which is sometimes undesireable. For the purpose of eliminating the above described disadvantage it is known to provide a reel changing device in which the said two strips are glued together before cutting, preferably by interposing between them a double sided adhesive tape, the two strips then being cut subsequent to their connection. Such a reel changing device eliminates the possibility that discontinuity of the strip should occur, but introduces significant structural complications given the evident difficulty of introducing the said adhesive tape between the strips and of subsequently cutting the strips after their connection.